松软破碎煤层巷道锚网支护关键因素

Key Factors Affecting Bolt-Mesh Supporting for Roadway in Soft-Broken Coal Seam

采用数值计算与正交试验相结合的方法,将影响松软破碎煤层巷道锚网支护效果的各因素组合为27种方案,并分别进行数值模拟.在低应力松软破碎状态下,以巷道顶底板的收敛量作为煤巷锚网支护效果的评价指标.通过对该评价指标的极差分析,得出影响松软破碎煤层巷道锚网支护的关键因素是锚杆间排距.不同锚杆间排距与巷道顶板下沉量的对应关系表明,当间排距这一关键因素大于650 mm时,对支护效果影响较为显著.最后,从锚杆与围岩共同作用的观点出发,分析了锚杆间排距成为松软破碎煤巷锚网支护关键因素的原因.

By using numerical method and orthogonal experiment, 27 experiment schemes are designed and analyzed. Under the low stress and soft-broken state of rocks, the convergence between roof and bottom of tunnel in soft-broken coal seam is taken as the index to evaluate the result of bolt-mesh supporting. Through the range analysis of the index shows that interval and spacing of bolts are the key influence factors of bolt-mesh supporting in soft-broken coal tunnel. The relationship between bolt spacing and roof subsidence shows that the key factors affect the result of support more evidently when the bolt spacing is more than 650ram. Finally, the reasons of the interval and spacing of bolts being the key influencing factors are analyzed from the viewpoint of joint action of bolt and surrounding rock.